Manufacture of multi-fold yarns

ABSTRACT

A multi-ply yarn is made by inserting unidirectional twist into two or more strands combined by feeding from separate feed points in converging paths to a combining point while increasing the separation of the converging strands against component forces acting on the strands, and then subsequently decreasing or allowing a decrease in the separation of the converging strands. Preferably the increase in separation of the converging strands is effected by a rotating cam.

United States atent 1191 [11] 3,5L9 Leach et a1. 1 1 Dec. 3, 1974MANUFACTURE OF MULTI-FOLD YARNS 788,292 4/1905 Verlenden 57/91 1,110,01591914 St 1 57 91 x [75] Inventors: Roger Leach, Shaw; Neil Doggett,1916377 7:19 K235? H 5J9] X Shuttleworth; James PP 2,731,789 1/1956Holder... 57/160 Middleton nr- Manchester, all 3,019,593 2/1962 Reid .157/156 Middleton NE. Manchester, all of 3,086,347 4/1963 Keen et a157/38.3

England FOREIGN PATENTS OR APPLICATIONS 73 A si nee: Platt InternationalLimited Oldham, 1 S g 213,619 11/1924 Great Britain 57/91 Lancashire,England [22] Filed: Jan. 111, 1973 [21] Appl. No.: 322,870

Primary Examiner-John Petrakes [30] Foreign Application Priority Data[57] ABSTRACT Jan. 14, 1972 Great Britain 1904/72 A multi-ply yarn ismade by inserting unidirectional twist into two or more strands combinedby feeding [52] US. Cl 57/91, 57/36, 57/38.3, from separate feed pointsin converging paths to a 57/90, 57/156 combining point while increasingthe separation of the [51] Int. Cl. DOlh 13/02, DOlh 1/02 convergingstrands against component forces acting [58] Field of Search 57/90, 91,34 R, 36, 38.3, on the strands, and then subsequently decreasing or57/156, 157 R, 160 allowing a decrease in the separation of theconverging strands. Preferably the increase in separation of [56]References Cited the converging strands is effected by a rotating cam.

UNITED STATES PATENTS 771,720 10 1904 Damon 81211. 57/91 6 4 Drawmg Thepresent invention relates to a method of and apparatus for spinningmulti-ply yarns.

It is known to make a two-ply yarn by inserting, by means of a ring andtraveller a uni-directional twist into two strands combined by feedingthem from separate feed points through a strand converging guide whichcauses them to follow converging paths and which is oscillatedcontinuously to vary the length of each strand path between its feedpoint and the point at which the strands combine. The strand convergingguide comprises a strand collecting ring or arrangement of fingers whichconverges the strands and which is oscillated by means of a cam andlever arrangement, excursion of the ring or finger arrangement in onesense moving the converging strands against strand tension into strandpaths in which they combine progressively closer to the feed points andexcursion of the ring or finger arrangement in the opposite senseallowing the strands to return to strand paths in which they combineprogressively further away from the feed points.

The arrangement for varying the strand paths hereinbefore described ishowever crude and produces a low level of strand twist in the yarn woundon to the ring and traveller, because the twist changes are carried outslowly.

The present invention seeks to improve strand twist levels in suchyarns.

According to one aspect of the present invention, there is provided amethod of making a multi-ply yarn comprising the steps of insertinguni-directional twist into two or more strands combined by feeding themfrom separate feed points in converging paths to a point of which theycombine while increasing the separation of the converging strandsagainst component forces on the strands and then subsequently decreasingor allowing a decrease in the separation of the strands.

According to a second aspect of the present invention, there is providedapparatus for making a multi-ply yarn comprising twisting means forinserting unidirectional twist into a strand formation in which two ormore strands are combined and means producing the strand formation andapplying it to said twisting means comprising feeding means for feedingsaid two or more strands from spaced feed points in converging paths toa combining point at which they combine to form said strand formationand strand separating means for increasing the separation of theconverging strands against component forces on the strands, and

then subsequently decreasing or allowing a decrease in the separation ofthe converging strands.

Two embodiments of the invention will now be described by way of examplewith reference to the accompanying drawing in which:

FIG 1 is a perspective view of apparatus according to the invention;

FIG. 2 is a front view of a cam employed in the apparatus shown in FIG.1;

FIG. 3 is a developed plan of an alternative cam which may be employedin apparatus according to the invention; and

FIG. 4 is a plan view of the cam shown in FIG. 3. Referring firstly toFIG. 1, two strands 8 and 10 in the form of worsted rovings are fed by aconventional apron drafting system 2 to a pair of delivery rollers 6 and7, which advance the strands 8 and 10 at constant and equal speeds fromthe nip thereof at spaced points 12 and 14. The strands 8 and 10 passover converging camming edges 9 and 11 of a rotary cam 18, from whichthe strands converge to combine and be twisted into a two-ply yarn by aconventional ring and traveller take-up device, which has a lappet 4 andis shown sche-' matically at 42'. The unidirectional twist imparted tothe yarn by the take-up device causes the converging strands 8 and 10 tocombine at a combining point 30 with twist induced by the unidirectionaltwist into the strands. The distance of the convergence point from thefeed points 12 and 14 is varied as hereinafter described by varying theseparation of the converging strands under the control of the cam 18.

The cam 18, which is mounted on a drive shaft 20 driven by electricmotor 22 through a speed reduction drive now shown, is arrangedcontinuously to rotate in the direction indicated by the arrow A in thedrawing, The cam 18 has a central web 24 which supports a cam portion 26which lies in a cylindrical surface having an axis coincident with therotary axis of the drive shaft 20. The cam portion 26 is of triangularshape and extends over an arc of the cylindrical surface of about 210,the web 24 being cut away so as not to extend beyond the arc of the cam18.

In operation, the cam 18 is rotated at about rpm and the two strands 8and 10 are delivered by the delivery rollers 6 and 7 at a feed speed ofabout 15 m/min. Upon each revolution of the cam 18, a nose 28 thereofenters the space between the strands 8 and 10 which without restraintfrom the cam 18 converge along paths of minimum separation as shown inbroken line in the drawing, to a combining point 16 where they combineand become twisted together by the take-up device. As the cam 18 rotatesthe camming edges 9 and 11 come to bear against the two strands 8 and 10causing them to increase their separation as shown in full line in thedrawing, thereby bringing the point 30 at which they combine topositions progressively further away from the feed points 12 and 14. Theposition of the yarn relative to the axis of rotation of the cam 18 issuch that before the strands are dropped from the trailing edge 32 ofthe cam the nose 28 of the cam re-enters the space between the strandsand the edges 11 and 9 take up the strands from the trailing edge. Thusthe convergence point 30 is caused to move still further toward thelappet 4 until the cam has turned through a sufficient angle that thetrailing edge 32 has passed between the strands for the second time thusproducing the position of maximum separation. When dropped from thetrailing edge the strands are free to return to the original separationunder the influence of tension and the twist inserted by the ring andtraveller 42'. The strands are free until the cam has completed 360 fromthe original position whereupon the nose 28 re-enters the space be tweenthe strands as shown in FIG. 1 for another cycle.

The component forces which act on the strands during combining are thetension on each strand acting on a direction away from the combiningpoint towards the cam, the tension on the twofold yarn acting away fromthe combining point towards the take-up device; the torque on thetwofold yarn; the torque on each strand; and a small couple on thecombining strands derived from the tension in the strands and the smallbut finite separation of the strands in the twofold yarn.

An alternative form of cam for carrying out the invention, shown inFIGS. 3 and 4, is formed from a separating barrel cam element 40arranged between two outer barrel cam elements 41 and 42 and all carriedon a common shaft 43. I

The separating cam element 40 has a cam portion 44 which is oftriangular shape and which extends over a cylindrical surface of about210 and the cam portion 44 presents camming edges 45 and 46 whichconverge at a nose 47 and which are separated by a maximum distance atthe trailing edge 48 of the separating cam element 40. The underside ofthe camming edges 45 and 46 is cut away so as not to interfere with thestrands 8 and 10.

The outer cam elements 41 and 42 have undercut guide edges 49 and 50which are arranged adjacent to and are of corresponding shape to therepsective camming edges 45 and 46 whereby to define strand passages 51and 52 therewith on either side of the separating cam element 40. Therear portions 49a and 50a of the guide edges 49 and 50 convergegradually towards each other behind the trailing edge of the separatingcam element 40.

In operation the cam is rotated and the cam portion 44 of the separatingcam element 40 acts to increase and decrease the separation of thestrands in the same manner as the cam portion 26 of the cam describedwith reference to FIGS. l and 2. However in this embodiment as thestrands leave the camming edges 45 and 46 at the trailing end 48 of theseparating cam element 40, they contact repsective rear portions 49a and50a of the guide edges 49 and 50 of the outer cam elements 4] and 42 andare positively guided thereby towards each other to return to theirpaths of minimum separation.

When the yarn produced by the apparatus hereinbefore described withreference to the drawings is untwisted to remove the uni-directionaltwist insertd by the ring and traveller it is seen that each strand hasrepeated along its length alternating zones of opposite twist of an 8232repeating pattern, each twist zone being about cm long.

An advantage of the method and apparatus according to the invention isthat no twist-restricting force is placed upon the strands as theirseparation is increased or during the subsequent decrease in separation.More twist is thus incorporated into the yarn as strand twist.

We claim: 1. Apparatus for spinning a multi-ply yarn comprismg:

feed means for feeding two strands from spaced points in convergingpaths to a combining point,

twisting means downstream of the combining point for inserting twistinto the combined strands which runs back to the combining point,

separating cam means having first and second camming edges and arrangedbetween the feed means and the combining point,

separating cam drive means for rotating said separating cam meanswhereby one edge of the separating cam means engages one of theconverging strands and the other edge of the separating cam meansengages the other of the converging strands to increase progressivelythe separation of the strands to a maximum separation whereupon thestrands disengage from said camming edges and decrease in separation.

2. Apparatus for spinning a multi-ply yarn comprising:

feed means for feeding two strands from spaced points in convergingpaths to a combining point,

twisting means downstream of the combining point for inserting twistinto the combined strands which runs back to the combining point,

a separating cam having a pair of mutually inclined camming edges whichconverge at a leading edge of the cam and which have their maximumseparation at a trailing edge,

separating cam driving means for rotating said separating cam, wherebythe leading edge of the separating cam enters between the convergingstrands and the strands pass along respective camming edges to increasethe separation of the strands to a maximum at the trailing of theseparating cam and whereby the strands are released from the cammingedges at the trailing edge of the separating cam and decrease inseparation.

3. An apparatus as claimed in claim 1 and further including guide meanswhich engage with the strands as they are released from the cammingedges and guide them towards one another.

4. An apparatus as claimed in claim 3 wherein the guide means includestwo further cams arranged one on each side of the separating cam androtatable therewith, a guide edge on each of said further cams having aportion adjacent the trailing edge of the separating cam, the saidportions of the guide edges gradually converging towards each otherbehind the trailing edge of the separating cam whereby the strands arepositively guided towards each other after they have been released bythe separating cam.

5. An apparatus as claimed in claim 4 wherein each guide edge includes afurther portion adjacent to, and corresponding in shape to a respectiveone of the camming edges of the separating cam whereby to define apassage between the further portion of the guide edge and the respectivecamming edge.

6. An apparatus as claimed in claim 2 wherein the camming edges areprovided on a part cylindrical sur-

1. Apparatus for spinning a multi-ply yarn comprising: feed means forfeeding two strands from spaced points in converging paths to acombining point, twisting means downstream of the combining point forinserting twist into the combined strands which runs back to thecombining point, separating cam means having first and second cammingedges and arranged between the feed means and the combining point,separating cam drive means for rotating said separating cam meanswhereby one edge of the separating cam means engages one of theconverging strands and the other edge of the separating cam meansengages the other of the converging strands to increase progressivelythe separation of the strands to a maximum separation whereupon thestrands disengage from said camming edges and decrease in separation. 2.Apparatus for spinning a multi-ply yarn comprising: feed means forfeeding two strands from spaced points in converging paths to acombining point, twisting means downstream of the combining point forinserting twist into the combined strands which runs back to thecombining point, a separating cam having a pair of mutually inclinedcamming edges which converge at a leading edge of the cam and which havetheir maximum separation at a trailing edge, separating cam drivingmeans for rotating said separating cam, whereby the leading edge of theseparating cam enters between the converging strands and the strandspass along respective camming edges to increase the separation of thestrands to a maximum At the trailing of the separating cam and wherebythe strands are released from the camming edges at the trailing edge ofthe separating cam and decrease in separation.
 3. An apparatus asclaimed in claim 1 and further including guide means which engage withthe strands as they are released from the camming edges and guide themtowards one another.
 4. An apparatus as claimed in claim 3 wherein theguide means includes two further cams arranged one on each side of theseparating cam and rotatable therewith, a guide edge on each of saidfurther cams having a portion adjacent the trailing edge of theseparating cam, the said portions of the guide edges graduallyconverging towards each other behind the trailing edge of the separatingcam whereby the strands are positively guided towards each other afterthey have been released by the separating cam.
 5. An apparatus asclaimed in claim 4 wherein each guide edge includes a further portionadjacent to, and corresponding in shape to a respective one of thecamming edges of the separating cam whereby to define a passage betweenthe further portion of the guide edge and the respective camming edge.6. An apparatus as claimed in claim 2 wherein the camming edges areprovided on a part cylindrical surface.